This is a a single-centre, parallel, randomized controlled trial in women with gestational diabetes mellitus (GDM). Women are randomized to routine monthly prenatal clinic care (standard care group) or a group sending daily glucose readings via an application installed on a smartphone and monthly individual videoconferences replacing in-person visits (telemedicine group). The overall aim is to compare the effectiveness of the combine synchronous and asynchronous telemedicine care with the standard care in women with GDM.

In our single-centre, parallel, randomized controlled trial in women with gestational diabetes (GDM) the investigators aim to compare the effectiveness of combined synchonous and asynchronous telemedicine care with the standard care.

In the telemedicine group appointments are performed online via monthly scheduled videoconferences. Women also receive a smartphone with the installed application that enable transfer of the measured capillary glucose concetration at the same time it is performed. The glucose data sent by women are reviewed once per week and after that healthcare professionals contact women if necessary. On the other hand, in the standard care group, visits are scheduled normally on a monthly basis at the diabetes clinic.

Intention-to-treat analysis is going to be performed. The investigators aim to compare glycemic control, gestational weight gain and perinatal data between groups.

Student's t-test or Mann-Whitney U test will be used for normally or non-normally distributed variables. Differences between groups in categorical data will be calcuated by Chi square.

Inclusion Criteria:

• less then 30 weeks of gestation at enrolement
• GDM diagnosis
• at least moderate Slovenian language skills
• willingness to participate

Exclusion Criteria:

• more than 30 weeks of pregnancy
• overt diabetes or fasting glucose >6.9 mmol/l at diagnosis
• multiple pregnancy
• poor Slovene language skills
• history or bariatric surgery or other surgeries that induce malabsorbtion
• use of systemic steroids prior to enrolment
• presence of concomitant disease that could affect glucose control or self-management (e.g. uncontrolled psychiatric disorder)